How Big-League Bats Are Getting Harder Than Ever

Buster Posey of the San Francisco Giants singles against the Colorado Rockies on Sept. 19. Players have embraced maple bats in recent years, believing a harder bat transfers more energy to the ball. The company behind the iconic Louisville Slugger says it has come out with the hardest bat ever. Photo: Marcio Jose Sanchez/Associated Press

Ted Williams looked for bats with knots in the barrel because, he thought, the compressed wood within the gnarls would return more energy upon impact with a pitched baseball. It’s the same reason that, dating back generations, players have worked over their bats by rubbing an animal bone lengthwise across the barrel, packing the raised grains of the wood and create a tight, level hitting surface.

It’s an ongoing quest for impermeability, which over recent years has led to the widespread use of maple bats — which are harder than traditional ash bats — and a variety of finishes. Never mind that testing has yet to draw conclusive results that this actually helps; the fact is Barry Bonds used a maple bat to swat 73 home runs in 2001, and a cavalcade of copycats quickly followed.

Now, Hillerich & Bradsby, maker of the famed Louisville Slugger, has upped the ante with its MLB Prime line, hitting stores Oct. 1. It called the Prime the hardest bat ever. In so doing, the company achieved two goals: It improved a product it provides to some 400 major leaguers, and it found a way to replicate the process en masse to make the bats commercially available.

The innovation, which applies to both maple and ash bats, begins with a vacuum drying process — a combination of heat, time (typically between four and five days) and negative pressure — that removes moisture consistently throughout the wood. For the last half-century, kilns have been used to dry bats, but the process can leave moisture at the center of the lumber.

“It took some doing to get this right. If you apply the vacuum too hard, or use too much heat, you can rupture the cells and destroy the wood,” said Bobby Hillerich, the company’s director of wood bat manufacturing, and a direct descendent of J.F. Hillerich, the man who turned his first bat in 1884 and started a company that has been passed down through generations. “My great-grandfather would be absolutely jealous of the process we’re using.”

The company also takes the boning process, which is used not only by baseball players, but bat manufacturers, up a notch with a compression device that applies force to 360 degrees of the bat’s hitting surface. It’s essentially a high-tech polisher that delivers 500 pounds of pressure, compressing the soft grain and equalizing the surface of the bat to afford a consistent hitting area.

The final factor is the finish, which Hillerich & Bradsby claims is the hardest on the market, owing to the fact that its 9H hardness rating is the highest ASTM International offers. Previously, the company’s bats rated only 5H.

“When we moved to downtown Louisville in 1996, we had to change our finish to meet air quality regulations,” said Hillerich. “In the past few years we’ve noticed that some of our competitors have edged forward with a harder finish, and we knew that we had to meet that challenge. The easiest thing would have been to change to an oil base and finish the bats somewhere other than downtown Louisville, but after three years and five different finish companies, we found a water-based finish that is the hardest in the industry.”

There’s also the part about making the bats widely available. Creating 120,000 bats for professional ballplayers is one thing, but distributing the product widely is something different. This has primarily to do with the wood procurement process, which once involved sifting through mountains of lumber to find the 23 percent (or so) of wood with quality high enough to suit major leaguers.

Today, the company has a full-time forester seeking specific logs of veneer-grade quality, with between six and 12 rings per inch. The logs are vetted before they ever reach the warehouse. This new process offers a typical yield of about 65 percent — high enough to allow for a much larger production run. The company runs four vacuum drying machines, which hold an average of about 2,300 bats apiece.

“Trust me, trying to get a 128-yr-old company to change the way it look at a product can be rather difficult sometimes,” said Hillerich. “But boy was this worth it.”